Access variable from function inside of nested function [duplicate]

Question

In PHP, you have to use the global keyword in order to access a variable from the global scope when inside of a function. However, how can you access a variable within the scope of a parent function?

In the example:

function foo() {
    $content = 'foobar';

    function bar() {
        echo $content; // echos nothing
    }
}

How can I access the $content variable?

Answer 1

You have two options:

1. Give $content as a parameter

   function foo() {
       $content = 'foobar';
   
       function bar($content) {
           echo $content . '1'; // 'foobar1'
       }
   
       bar();
   }
   
   foo();
   

2. Use closures (PHP Manual) (PHP 5.3.0+)

   Please note that the function declaration is a bit different compared to the 'conventional way' of declaring functions.

   function foo() {
       $content = 'foobar';
   
       $bar = function() use ($content) {
           echo $content . '1';
       };  // <-- As it's an assignment, end with a ';'
   
       $bar();
   }
   
   foo();  // 'foobar1'